High tumour-associated macrophages infiltration is correlated with poor survival outcome in classical Hodgkin’s lymphoma

Background: Classical Hodgkin’s lymphoma (cHL) represents the majority of HLs with a relatively good prognosis. In 20% ofpatients, primary treatment fails. Prediction of treatment failure is critical. A gene signature of tumour associated macrophages(TAM) correlated with response to treatment as CD68 positive TAM was found to be associated with shortened survival. We aimto investigate the relation CD68+TAM infiltration to patients’ outcome. Patients and Methods: Pathological materials of 115 patients with cHL were used. Clinical characteristics of patients werecollected from the records. CD68 immunostaining was performed to determine the number of infiltrating TAM and subsequentlyfollowed by stratification of results. Results of CD68 immunostaining were statistically analysed to correlate the extent of CD68+TAM infiltration with clinicopathological characteristics, treatment outcome, and patients’ survival. Results: High CD68+TAM infiltration was observed in more patients of cHL (96/115 of patients = 83.5%). High CD68+TAMinfiltration was associated with extranodal presentation (p = .001), and higher stage (p = .022). No associations with otherclinicopathological parameters were found. High CD68+TAM infiltration was not found to be an independent predictor oftreatment outcome. High CD68+TAM infiltration correlated with disease free survival (DFS) (log-rank = 4.505, p = .034) but notwith disease specific survival (DSS) (log-rank = 1.371, p = .242). Conclusions: The results of our study support the adverse prognostic effect of high TAM in cHL. Technical standardisation ofCD68 immunostaining is required to establish TAM infiltration as a prognostic predictor. Also in vivo and in vitro cHL modelshave to be established for proper understanding of the role of CD68 in modulating the TAM in cHL.